Method of heat treating axles



May 10, 1932. B. H. URscHr-:L 1,857,895

METHOD oF HEAT TREATING AxLEs Filea Aug. 2s. 195o Pamesa May 1o, 1932 UNITED STATES PATENT ori-ICE BERTIB H. URSOHEL, F BOWLING GREEN, OHIO, ASSIGNOB T0 URSCHEL ENGINEERING COMPANY, 0F TOLEDQDHIO, A CORPORATION OF O HIO IETHOD 0F HEAT TREATING AXLES Application illed August 88, 1980. Serial No. 477,813.

My invention has for its object to rovide a method of heat treating steel mec anical elements havin metal parts bonded therein by the contraction of the enclosing metal of 5 the mechanical elements. The invention particularly provides. for tightly securing auxiliary steel bearing or reenforcing parts in steel mechanical elements that are to be hardened by raising the temperature to a relatively a high point, subsequent quenching and then drawing at a certain temperature depending on the hardness that is desired to produce within the body of the mechanical element.

In the conduct of the method involving my invention, the mechanical element is heated to a desired temperature, and the enclosed auxiliary parts are chilled, in advance of the quenching ci the mechanical element, in such a manner that the metal of the parts will 2o have desired reduced dimensions that approximate the dimension of the arts when at normal temperatures, which gives opportunity for the metal of the body of the mechanical element to reely contract and tightly secure the auxiliary parts within the body of the mechanical element when it is quenched and drawn. Thus the enclosed parts first chill when the metal of the body of the element tightly draws about the said parts, while, if so the mechanical element is quenched without iirst chilling the parts, the metal of the element will be stretched, and the metal of the parts will be compressed and subsequent chilling of the parts by the conduction of the heat through the chilled body of the element Y will leave the parts loose within the body of Y the element. lf desired, the temperature of the parts may be maintained to prevent excess chilling of the parts when the body of the element is'chilled and thus prevent excess hardening of the parts.

The invention finds particularly advantageous results when used in the formation of steel tubular members. such as struts, tierod,.axles, and other load carrying members, or pivotally connected. parts of mechanisms.

The methods involvedin my invention may be used for manipulating steel structures of di'erent forms and which vary in their o9 shape and details according tothe uses to which they are put.l To illustrate a practical application of the invention, I have selected the method of'forming the tubular axle wherein my invention finds particular advantageous results and wherein stub axle hearing members are enclosed or surrounded by the metal of the body ofthe axle, and also. wherein reenforcing load carrying tubular' members are located at the points in the axle' to 'which the spring clamps or saddles are connected, as illustrative of the methods that utilize my invention, it being understood that the method particularly described may be modified in its details or steps of operation without departing from the spirit of the invention. As an aid in the description of the method of operation particularly referred to, I have illustrated, in the accompanying drawings, an axle, an auxiliary bearing and reenorcing parts. The process and the apparatus used in carrying out the processes are described hereinafter, as well as the article produced by the process.

Fig. 1 illustrates a view of a section of a trough having anvils and clamping members, and means for positioning the clamping members relative to each other. to locate the centers in their proper relation to each other, and also to position the axes of the bushings in a definite relation to each other and to the body of the axle. Fig. E2 illustrates an enlarged View of an end part of the apparatus shown in Fig. 1 vand indicates one of the steps in the process of heat treating the axle. Fig. 3 is an enlarged view of a. transverse section of a part of the axle.

ln the heat treatment of the axle, the temperature is raised to approximately 1500 de grees Fahrenheit. and the axle is then quenched in water and drawn at a temperature of 1000degrees to 1200 degrees Fahrenheit to produce :in-elastic limit of 140,000 to 160,000 pounds, but where axles contain members that are tightly enclosed in the body of the axle, quenching of the entire axle without previous heat treatment of such members, invariably results in producing a looseness between the surfaces of the members and the body of the axle, which produces a defective axle and, sooner or later, in the use of the axle,

'is tubular 1n with bushings 2 that are enclosed by the metal so as to be completely sur- The central parts of the ot the axle 1 and rounded thereby.

axle are provided with reenforcing steel tubes 3 that are located within portions of the tubular axle 1 to which the spring saddles or the springs are secured for connecting the axle to the vehicle. The tubes 3 preferably have a length suiliciently great to be enclosed by portions of the inner surface of the wall of the tube that are contiguous to the saddle or spring supporting portions 4 of the axle. The spring supporting portions of the axle may be shaped to more elliciently engage and secure the spring saddles, or springs themselves, to the axle at the u per and lower sides of the axle as at 5. A so, it desired, the reenforcing tubes may be correspondingly shaped to more etiiciently cooperate in the sustain- 'ment of the load. Usually a bolt extends through the axle that is used for securing a" spring saddle or a goose-neck to the axle and the axle is bored at this point. openings being formed through the upper and lower sides of the reenforcin g tubes 3 and the body of the axle. If the spring saddle or the springs are secured by U-bolts or clips. that surround the springs. or the spring saddles. small openings may be formed in the lower sides of the body ot the axle and the reeuforcing tubes 3 to permit introduction of the chilling fluid into the reentorcing tubes in advance of the quenching of the body of the axle. l

In carrying out the process involving the use of my invention. I provide means for introducing water or steam. preferably. into the interior of the bushings 2 and the reenforcing tubes 8. in advance ot the quenching of the body of the axle. Preferably. water inthe form ot a spray is directed into the bushings 2 through the lower ends ot the bushings and the steam is conducted away from. theupper ends ot the bushings. while the bushings and the ends ofvthe axles are held clamped in their positions. Also. water is preferably sprayed into the openings 7 formed in the lower sides of the reenforcing tubes 3 and the lower sides of the body of the axle 1. The steam may be conveyed away through the openings 8 formed in the upper sides of the reenforcing tubes 3 and the axli` l. Thusthc tubos 3 maybe chilled in advance.

of the chilling of the sa-me time that the bushings 2 are chilled.

To heat treat the axle, it is first raised to a relatively high temperature and is then placed in a trough, such as that illustrated in Fig. 1, which is provided with anvils 12 and 13. having upper surfaces that are shaped to conform to and to engage and socure end parts ofthe axle, and to secure load. supporting parts of the axle and' also clamping members 14 and 15 having clamping surfaces that coliform to the upper surfaces of the end parts and the load supporting parts of the axle, whereby the said parts of the axle, when the axle 1s at the relatively high temperature, will be forced into proper relation to each other with reference to the body of the axle.

formed of two teleseoping parts and in ad- -V vance of -the quenchingof the axle, the anvils and their associated clamping parts may f body of the axle at the The parts of the axle will be forced into substantially the proper shape lao be shifted to either elongate or contract the axle lengthwise to properly position thece'n; ters. This may also be performed pneumatically or hydraulically or by means of a thread and Anut mechanism connected to the ends of the trough. In the 4form of construction shown, a pneumatic means -18 is conventionally shown as connected to each end of the trough. Thus in the quenchin operation, the heated axle 1 may be place( on the anvils 12 and 13, the clamps 14 andV 15 may be operated to clamp and properly align the parts `and then the clamps and anvils of one end of the trough may be drawn from, or movedtowards, the other end of the trough. may then be flooded to quickly submerge the axle and then evacuated to rapidly remove the clamps and anvils of' The trough the water. The water may be introduced by suitable mea-ns formed in opposite sides of the trough, such as the openings 20, and the water may able openings covered by the quick the traps 21 for subinergence and the rapid disbe allowed to escape through suitcharge of the water,- whereby all parts ot the axle are subjected to substantially the saine chilling operation. In order to chill the members enclosed b the metal ot the body ofthe axle. the anvills 12 and 13 are provided with passageways Q3 and Q4 that communicate with the interior of the bushings 2 and thetubes 3, the

clamps 14 are also provided. with the passageways 25 and 26, which also communicate with the interior of the bushings 2 and the tubes 3. Pipes 27 are connected together and with the source of supply of Water,

whereby Water or steam may be directed into the interior of the bushings and the tubes at the same time. Preferably, the passageways 23and 24 terminate in nozzles 28 which will operate to distribute, or spray, the cooling fluid in all directions. .W'ater under pressure may be directed through the nozzles 28 and sprayed against the inner surfaces of the tubes and the bushings, and the steam allowed to escape through the upper pipes 29.

In the conduct ofthe process of heat treat-l ing the axle, subs uent to the location of the centers in their deslred relation to each other. as described, water under pressure is directed through the pipes 27 and, shortly thereafter, such as from three to tive seconds, depending on the sizes of the auxiliary parts that are embedded in'the bod v of the axle, the water is turned into the trough 10 to flood the axle through the opening 20 and, when the axle has been chilled to the desired temperature, the gates `'21 are open for quickly emptying the trough. The clamps 14 and 15 are then raised by theproper manipulation of the valves that control the pressure within the cylinder 16 and the axle is removed and is replaced by a succeeding axle which is in turn subjected to the pressure of the clamps 14 and 15 against the anvils 12 and 13 and the rtions of the axle of each end having the ushing 2 and the tube 3 are forced into proper alignment and relation .to each other and the centers of the parts of opposite ends are forced into their relation to each other by the operation of the pressure in the cylinders 18. The water is then sprayed against the inner surfaces of the bushings 2 and the reenforcing tubes 3. When these have cooled to a temperature that changes them into asolid, as distinct from semi-plasticity of the heated metal, the body of the axle is quenched by" flooding the trough 10 as before. This produces an axle wherein the bearing bushlng and the reenforcing tubes are tightly held and enclosed by the surrounding meta-l of the hardened axle.

If desired, the steel of the bearing bush ing may be formed of soft steel, such as the steel of bar stock metal having a low carbon content, and the steel body of the axle may be formed of a steel having a high carbon content, such as that of S. A. E. No. 1045. A fluid having a desired temperature may be directed through the pipes 27 and 24 and into the interior of the bearing bushings to gradually lower the temperature of the bushings or to maintain the temperature of the bushings within desiredlimitations for drawing or to maintain the metal of the bushings relatively soft and to produce relatively soft is being chilled.

machinable bushings While the metal of the body of the mechanical element, or axle, is chilled. During the treatment of the bearing bushings, the metal of the body portion of the axle may besubmerged or flooded, that is, quenched, to chill the body of the axle to produce a hardened condition in the body of the axle. This may be regulated by regulating the drawing temperature. There will thus be produced a soft, machinable bearing which, subsequent to the heat treating of the body of the axle. may be rebored or machined as may be desired. The softer metal of the bearing will thus be surrounded by the hardened elastic metal of the body of the axle.

The fluid is directed through the bearing members 2 and the axle rcenforcing.tubular part 3 to contract them in advance of the contraction of the surrounding metal of the body of the axle and prevent crushing of the bearing members and the reenforcing tubular pal'ts while they are in the semi-plastic state, and the metal of the body of the axle By cooling t-he bearing members and the reenforcing tubular parts in advance of the chilling of the body of theaxle, the metal of the bodyof the axle contracts about the solid members and reenforcing tubes to tightly enclose the same, and any amountof subsequent use of the axle will not cause these parts to loosen from the `-metal of the axle..

Iclaim/f y A 1. The process of forming a. mechanical clement which consists in venclosing metal auxiliary 4parts within the'body ofthe metal of the mechanical element, subjecting the element and the parts to a relatively high telnperature and directinga coolingfluid against the auxiliary parts, and subjecting .the body of the mechanica-l element to a cooling fluid. 2. The process of forming steel-mechanical elementshaving steel bearing parts, the steel of the mechanical element having a carbon content different from that of .the bearing parts, which consists in directing a temperature regulating fluid through the bearing parts for the desired length of time to maintain the desired drawing temperature in the bearings, and quenching the body of the -mechanical element to produce the desired hardening of the metal of the mechanical element while maintaining the metal of the bearing parts relatively soft and maehinable by the tempera-ture regulatingfluid directed'through the bearing parts. l

3. The process of forming a mechanical element' which consists in enclosing metal auxiliary parts within the body of the metal of the mechanical element subjecting the element and the parts to a. relatively high temy jecting the body of the mechanil element to lli).

Yclianical element from the cooling fluid at the desired temperature.

4. The process of forming steel mechanical elements having steel bearing parts, the steel of the body of the mechanical element having a carbon content different fromthat of the bearing parts, which consists in directing a temperature regulating fluid against the bearing parts time to produce the desired temperature in the bearings and subsequently quenching the body of the mechanical element to produce the desired hardening of the metal of the mechanical element.

5. The process of forming a tubular mcchanical element having enclosed coaxialreenforcing members, which consists in subjecting the axle to a relatively high temperature, directing a cooling iuid against the reenforcingfmemhers and shortly subsequent thereto, quenchingr the body of the mechanical element.

' 6. The process of forming steel mechanical elements having auxiliary supporting parts enclosed inl the metal of the body of the mechanical element, which consists in heating the body of the mechanicalelement to a relatively high temperature, forcing the said parts into definite relation to each other. clamping said parts to hold them in the said definite relation, againstthe surfaces of said parts.- quenching the metal of the body of the mechanical element while the mechanical element is held in its clamped position.

The process of forming tubular axles having bearing members and reenforcing members located in end portions thereof.

which consists in clamping said portions and forcing them into definite relation to each other` directing/a coolingluid against the 'surfaces of the said members. subsequently quenching the body of the axle while it is held in its clamped position.

8.l The process of forming tubular axles, which consists in placing reenforcing tubular members Within the vehicle supporting parts of the body of the axle and enclosing bearing members Within the end parts of the axle` forming openings in the upper and lower sides of the said parts of the axle having the reenforcing-tubes, directing a stream of the cooling fluid into the interior of the said members. subsequently quenching'thc body of the axle.

9. The process of`forming tubular axles, which consists in locating reenforcing ytubes Within the vehicle supporting parts of the axle and enclosing bearing members in the end arts of the axle, heating the axle to a relatively high temperature, and directing a cooling uid into the interior sur-faces of the members. and subjecting the body of the axle to a cooling Huid.

forthe desired length of directing cooling iuid.

10. .The process of forming 'a tubular axle 

